What is CSS and what is it used for?
CSS is a technology that defines the look and feel of a web page. It defines visual properties and styles of HTML elements.
Using CSS you can define colors, text fonts, types and sizes, borders, margins, paddings and many other visual aspects.
You can show and hide elements, set their position, create simple re-usable styles or design complex web page skins or themes.
CSS is a shortcut for Cascade Style Sheets.